/Engine/Source/Runtime/RHI/Public/RHICommandList.h
struct FRHICommandCopyBufferRegion : public [FRHICommand< FRHICommandCopyBufferRegion, FRHICommandCopyBufferRegionString__LINE__ >](API\Runtime\RHI\FRHICommand)
FRHIBuffer*...
DestBuffer
uint64
DstOffset
uint64
NumBytes
FRHIBuffer*...
SourceBuffer
uint64
SrcOffset